describe, in simple terms, the lattice structure of a crystalline solid which is: (a) giant ionic, including sodium chloride and magnesium oxide (b) simple molecular, including iodine, buckminsterfullerene \( C_{60} \) and ice (c) giant molecular, including silicon(IV) oxide, graphite and diamond (d) giant metallic, including copper
explain the variation in melting point and electrical conductivity in terms of the structure and bonding of the elements
define metallic bonding as the electrostatic attraction between positive metal ions and delocalised electrons